Don’t claim your paper contributes more than it actually does. (I refereed a paper this week where the author claimed to have invented principal component analysis!)

Ensure all figures have clear captions and labels.

Include citations to the referee’s own work. Obviously you don’t know who is going to referee your paper, but you should aim to cite the main work in the area. It places your work in context, and keeps the referees happy if they are the authors.